| Cover | Sep. 21, 2023 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 21, 2023 |
| Entity File Number | 001-40427 |
| Entity Registrant Name | GRAF ACQUISITION CORP. IV |
| Entity Central Index Key | 0001845459 |
| Entity Tax Identification Number | 86-2191918 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1790 Hughes Landing Blvd. |
| Entity Address, Address Line Two | Suite 400 |
| Entity Address, City or Town | The Woodlands |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77380 |
| City Area Code | 713 |
| Local Phone Number | 489-1772 |
| Written Communications | true |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Units, each consisting of one share of Class A common stock and one-fifth of one redeemable warrant [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Units, each consisting of one share of common stock and one-fifth of one redeemable warrant |
| Trading Symbol | GFOR.U |
| Security Exchange Name | NYSE |
| Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common stock, par value $0.0001 per share |
| Trading Symbol | GFOR |
| Security Exchange Name | NYSE |
| Redeemable warrants [Member] | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Redeemable warrants, each warrant exercisable for one share of common stock, each at an exercise price of $11.50 |
| Trading Symbol | GFOR. WS |
| Security Exchange Name | NYSE |
